The present invention relates to a seal between two elements which are insertable one in the other, especially pipes, preferably consisting of concrete.
Elements which are insertable one in the other, for example concrete pipes according to DIN 4032 and 4035, are usually sealed in relation to each other by means of elastomeric material seals which can be designed as roller rings or sliding seals. With regard to sliding seals DE-OS 29 00 437 describes a sealing ring for sealing the space between two substantially concentric sealing surfaces, the sealing ring consisting of two sealing portions each having a sliding surface, the sealing portions engaging each other at the sliding surfaces and being designed so that the sealing surfaces are maintained in substantially the same position when the sealing surfaces are introduced one in the other, engage a sealing surface each and slide against each other along the sliding surfaces. The sealing ring can be provided with a lubricant or sliding substance. In this embodiment of a sealing ring it is a drawback that the lubricant dries or hardens whereupon the sealing portions of the sealing ring can no longer efficiently slide against each other. This drawback is obviated in accordance with the European Patent Application EP 0 343 677 according to which there is proposed a seal between two prefabricated concrete elements which are insertable one in the other, wherein a sealing element is connected with one of the concrete elements and cooperates with a covering on the adjacent concrete element, the covering consists of a flattened hose filled with lubricant or a folded or single foil and the covering can be positioned on its concrete element just prior to the jointing of the concrete elements.
The sealing function of a seal, for example a seal according to the European Patent Application EP 0 343 677, is determined by the sealing force of the seal. When the sealing force is small, i.e. at a small deformation resistance of the seal, there is a risk of untightness, while a high deformation resistance provides for a more difficult jointing which may lead to fractures within the area of the pipe socket. Additionally there is in prefabricated concrete elements certain manufacturing tolerances providing for different space widths between tubular elements introduced one in the other, for which reason it is desirable to have access to seals sealing different space widths at one and the same sealing force.
For other fields of application it is desirable in a suitable way to be able to adjust the space width of the pipe joint and the sealing force of the seal in relation to each other.